R1150RT engine clattering at high rpm's

[AndyS]

A new problem developed over this last week.

When the engine is under light loads it runs sweet.

As the revs rise to the order of 4000 and with medium to high loads, I hear a clattering sound.

I have also detected an increase in oil consumption.

Any ideas.

[dirtrider]

Morning Andy

 

Without hearing the clattering it is very difficult to give you much specific guidance.

 

If the noise just started since your last fuel fill up then maybe a tank of very low octane gasoline in there.

 

I can't remember if you have a twin spark or not, if you do then make sure one of the lower plugs isn't oil fouled.

 

Otherwise the usual cause of higher RPM clatter on the BMW 1150 is a noisy cam chain or noisy front accessory shaft chain.

 

Rocker arm end play is usually a low RPM thing & throttle cam rattle is usually idle or just off idle so probably not those.

 

How is your throttle (twist grip position) verses vehicle speed (is it about the same as always?)

[AndyS]

I have run a few tank full of fuel through it.

It is a twin spark, but would a fouled lower plug cause much of a clatter?

The clatter generally chimes in on wider throttle settings (elevated load), or higher speed steady throttle (like 70mph) where the load on the motor is higher anyway.

 

Is it easy to break into the oil system to measure pressure?

 

Would a seized cam chin tensioner not cause clatter at low rpm's?

 

If I had a small end failure, what conditions would this show itself?

 

 

[Boffin]

If it sounds like a handful of marbles in a bean-tin then, form the load-related aspect of your description, it may be pinking. (pinging to the US members)

 

Perhaps time for a de-coke?

 

Andy

[dirtrider]

Afternoon Andy

 

Is it easy to break into the oil system to measure pressure?--- Yes, just remove the oil pressure light switch & take you pressure reading there.

 

Would a seized cam chin tensioner not cause clatter at low rpm's?---Yes, on a totally seized tensioner but on a chain guide issue, or worn tensioner it can cause chain noises at higher RPM's due to chain tracking & chain flutter (especially the front accessory chain as that can track out & contact the case).

 

If I had a small end failure, what conditions would this show itself?--- Usually gets worse as the engine heats (oil thins out) & as a rule more noticeable on light throttle-ups or short burst loads.

 

Lower plugs fouled can cause all kinds of spark knocking issues as the flame front then ONLY starts in the center & quickly compresses the outer fringes into a compression ignition. (single spark engine used a lamer spark curve)